This invention relates to an arrangement for mounting a rotation speed sensor to a wheel bearing assembly.
There is known a wheel bearing assembly carrying a wheel speed sensor assembly for detecting the wheel speed for use with e.g. an antilock brake system. Such a wheel speed sensor assembly comprises a magnetic ring mounted on a rotary member that rotates together with a vehicle wheel, and adapted to produce circumferentially alternating magnetic fields when it rotates, and a rotation speed sensor mounted on a stationary member fixed to the vehicle body for sensing the alternating magnetic fields produced by the magnetic ring and producing a wheel speed signal corresponding to the alternating magnetic fields. Ordinarily, the abovementioned rotary member to which the magnetic ring is mounted, is an inner member (inner ring) of the wheel bearing assembly, while the stationary member to which the rotation sensor is mounted, is an outer member (outer ring) of the wheel bearing assembly.
The rotation sensor is mounted to the stationary member so as to oppose the magnetic ring. The rotation sensor has to be mounted as stably as possible So as not to shake. If the sensor fails, it has to be removed for repair or replacement. For this purpose, mounting and dismounting of the sensor should be as easy as possible. JP patent publications 6-308145, 9-263221 and 2000-221203 disclose wheel bearing assemblies carrying a rotation sensor which is snapped on a stationary member of the bearing assembly. Such a snap-on sensor can be easily mounted to and dismounted from the stationary member.
In any of these publications, the rotation sensor is mounted to the stationary member (ring) through an annular support member. That is, the support member is directly mounted to the stationary member, and a case of the rotation sensor is snapped on in the support member by elastically deforming the case. In JP publication 6-308145, the annular support member, too, is snapped on the stationary member so as to be dismounted from the stationary member. In the other two publications, the support member is fixed to the stationary member, so that only the wheel speed sensor is dismountable.
In these conventional arrangements, the annular support member has a first mounting portion mounted to the stationary member and a second mounting portion coupled to the sensor. The sensor is thus mounted to the stationary member through the two discrete mourning portions of the support member. Thus, the sensor is likely to shake or loosen relative to the stationary member. Also, the two discrete mounting portions complicate and make bulky the support member, and also increase its cost. Also, a wide installation space is required.
An object of this invention is to provide an arrangement for mounting a rotation sensor on a wheel bearing assembly with which the rotation sensor can be easily, directly, stably and detachably mounted to the stationary member of the wheel bearing assembly.